The present invention relates to the retention and protection of spliced optical fibers. More specifically, the invention relates to an arcuate retainer for organizing and securing fiber optic splices.
Communications networks are frequently made of many miles of optical fibers. Indeed, many of the networks can extend between continents and across oceans and other large bodies of water. For protection, the optical fibers are contained in a larger cable. An example of such a cable is shown in FIG. 1. The cable 2 includes an outer insulating plastic coating 4, a copper sheath 6 inside the outer coating 4, and high strength members, such as steel wires 8, inside of the copper sheath 6. A loose tube 10 is contained within the steel wires 8, and one or more isolated optical fibers 12 are contained within the loose tube 10. This permits the fibers 12 to move with respect to the steel wires 8, the sheath 6 and the coating 4. This cable arrangement has been found to be desirable in many high strength applications.
As neither the cables nor the fibers can be made and deployed in infinite lengths, sections of the cables and the fibers are attached together. The fibers are typically attached to each other by a process known as splicing. For protection from the environment, these spliced sections are commonly contained in a watertight housing, which is frequently referred to as a joint box. Such housings or joint boxes are also used when it is necessary to make splices in the field.
In circumstances when tension is applied to the cable, such as during the deployment of the cable underwater by a ship, it is undesirable to have the splice absorb the forces. Thus, on either side of the splice, a great deal of slack, such as three feet of fibers, may be provided to prevent the splice from being stressed. The joined fibers, with their slack, may be coiled onto a center section of the joint box, wound around cylinders or stored in magazines adjacent a center section of the joint box. The splice itself is fixed within the center section.
Traditionally, multiple splices are placed in each joint box. However, most arrangements do not make efficient use of the limited space in a joint box and do not adequately restrain splices to prevent damage. Thus, a need exists to organize splices in a manner that does not lend itself to damaging the splices and makes efficient use of limited space in a joint box.
In view of the foregoing, it is an aspect of the present invention to provide an arrangement for organizing and protecting spliced optical fibers in a joint box.
It is a further aspect of the present invention to provide an arcuate splice retainer for retaining a plurality splices. The retainer may be in a joint box and may include a first arcuate-shaped storage channel for retaining more than one of the plurality of splices. The retainer may include a first element having a convex surface forming a bottom portion of the first channel, and a second element having a concave surface forming a top portion of the first channel and retaining the more than one splices in the first channel between the first and second elements. The first element may include a center step and end steps in the lateral ends of the first element. The center step and the end steps may extend the length of the first retainer. The retainer may further include a second arcuate-shaped storage channel for storing more than one of the plurality of splices, wherein the second channel is radially spaced from the first channel with respect to a longitudinal axis parallel to longitudinal axes of said plurality of splices. The retainer may also include a third element having a concave surface forming a top portion to the second channel, and the second element having a convex surface forming a bottom portion to the second channel. The splices in the first and second channel may be secured in a static position. The retainer may further include a third arcuate-shaped storage channel angularly spaced from the first channel and radially spaced from the second channel with respect to the longitudinal axis, wherein the third channel is for retaining more than one of the plurality of splices, and the first and third channels are separated by the center step. The second element may be removably attached to said first element, and the third element may be removably attached to the second element.
A further aspect of the present invention may include a joint box with a middle section and a center shelf. The center shelf may longitudinally divide the middle section into first and second compartments, and a first retainer may be positioned on the center shelf in the first compartment. A second retainer may be positioned on the center shelf in the second compartment.
Another aspect of the present invention may include a fiber optical network, and the joint box and splices of the present invention may be a part of the fiber optical network.
The above and other features and advantages of the present invention will be readily apparent and fully understood from the following detailed description of preferred embodiments, taken in connection with the appended drawings.